diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py
index b5155b4..d173ae1 100644
--- a/Lib/test/test_time.py
+++ b/Lib/test/test_time.py
@@ -119,6 +119,16 @@
     def test_asctime(self):
         time.asctime(time.gmtime(self.t))
         self.assertRaises(TypeError, time.asctime, 0)
+        self.assertRaises(TypeError, time.asctime, ())
+        # XXX: Posix compiant asctime should refuse to convert
+        # year > 9999, but Linux implementation does not.
+        # self.assertRaises(ValueError, time.asctime,
+        #                  (12345, 1, 0, 0, 0, 0, 0, 0, 0))
+        # XXX: For now, just make sure we don't have a crash:
+        try:
+            time.asctime((12345, 1, 0, 0, 0, 0, 0, 0, 0))
+        except ValueError:
+            pass
 
     def test_tzset(self):
         if not hasattr(time, "tzset"):
diff --git a/Modules/timemodule.c b/Modules/timemodule.c
index d6d4160..a59d3f0 100644
--- a/Modules/timemodule.c
+++ b/Modules/timemodule.c
@@ -546,6 +546,10 @@
     } else if (!gettmarg(tup, &buf))
         return NULL;
     p = asctime(&buf);
+    if (p == NULL) {
+        PyErr_SetString(PyExc_ValueError, "invalid time");
+        return NULL;
+    }
     if (p[24] == '\n')
         p[24] = '\0';
     return PyString_FromString(p);